P1641: RECURRENT VENOUS THROMBOEMBOLISMS AND ANTICOAGULATION COMPLICATIONS; A PROSPECTIVE STUDY.
Authors: Teymur Nasibov, Noorusamah Fyzul, Patrick Kiely, Michael Watts, Denis Okeeffe
Journal: HemaSphere (2023)

Topic: 34. Thrombosis and vascular biology - Biology & Translational Research Background: Recurrence of venous thromboembolism (VTE) is associated with high mortality and morbidity but anticoagulation also confers high risks. Cancer, Antiphosholipid Syndrome, vascular disorders, Heparin induced Thrombocytopenia, and Pregnancy are a few known causes for recurrence. Although the acute treatment phase of VTE is 3 months, it is known that the residual effects of prior VTE remain in a significant number of patients eventually causing post thrombotic syndrome. These residual effects can mimic the appearance of acute thrombosis on Venous Doppler, and thus mimic a recurrent thrombotic event. This has the potential to result in a clinical recommendation for continued and possibly life long anticoagulation, with the inherent, potentially unnecessary bleeding risks associated. Elastography, compression and vein diameter are a few methods adopted by radiologists to distinguish between old and new clots on ultrasound. However this requires previous scans for comparison and has limitations. We propose that a Multidisciplinary Meeting (MDM) is vital to confirm if recurrence is indeed true given the significant impact on patient management. Aims: This study aims to assess the value of MDM review of recurrent VTE, which combines radiology, clinical history and d-dimer to evaluate whether a thrombus is truly recurrent. Prospective follow up of patients was then carried out to determine if the MDM decision was correct. Methods: All patients reviewed in the Thrombosis MDM meeting between 2019 and 2021 who were defined as recurrent VTEs were included in this study. The MDM consists of comparing the prior and new scans by an expert Consultant Radiologist in discussion with the Consultant Haematologist and Physician. The clinical presentation, D-dimers, risk factors, treatment regimes, complications and MDM outcome were noted. These patients served as a cohort that were followed up by prospective analysis to 2023 to determine if these patients had further VTEs or anticoagulation related complications based on clinical and radiology review. Results: 45 patients were identified with a recurrent PE (8, 17.8%) or DVT (37, 82.2%). After MDM review, 22 (48.9%) were determined to have evidence of previous VTEs without features of a new VTE. 8 of these 22 patients (36.4%) had an elevated d-dimer with 9 (40.9%) being negative. 19 (42.2%) were deemed to be new and 4 (8.89%) were indeterminate but treated as new. Active treatment was ceased in 10 (22.2%) and 4 (8.89%) had already completed 3 months of anticoagulation prior to MDM. The 3-month anticoagulation course commenced on diagnosis was completed in those who were significantly symptomatic with persisting risk factors (8, 17.8%). 19 (42.2%) patients who were deemed no new VTE had their anticoagulation stopped by three months while 3 (6.66%) were reverted to their prophylactic life-long anticoagulation. Life-long anticoagulation was started in those with a new event where at least one thrombus was deemed to be unprovoked 20 (44.4%). On follow up 20 (44.4%) patients had repeat scans to evaluate further events with only 1 (2.22%) being positive for a breakthrough event. This patient had underlying cancer and was on anticoagulation at this time. Summary/Conclusion: MDM review of patients presenting with recurrent VTE is vital. Clinical assessment with radiology evidence enabled 48.9% of patients to have their diagnosis of a new VTE changed thus allowing cessation of anticoagulation in 42.2% and reversion to prophylaxis in 6.66%. One of these patients on long-term anticoagulation had a subsequent VTE with progression of their lung malignancy. Keywords: Pulmonary embolism, Anticoagulation, Venous thromboembolism, Deep venous thrombosis